CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2021-42717
High (7.5). EPSS 3.2% chance of exploitation in the next 30 days.
ModSecurity 3.x through 3.0.5 mishandles excessively nested JSON objects. Crafted JSON objects with nesting tens-of-thousands deep could result in the web server being unable to service legitimate requests. Even a moderately large (e.g., 300KB) HTTP request can occupy one of the limited NGINX worker processes for minutes and consume almost all of the available CPU on the machine. Modsecurity 2 is similarly vulnerable: the affected versions include 2.8.0 through 2.9.4.
Severity
- EPSS
- 3.2% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-31)
- CWE
- CWE-674
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- f5:nginx_modsecurity_waf
- oracle:http_server
- oracle:zfs_storage_appliance_kit
- owasp:modsecurity
- trustwave:modsecurity
References
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html
- https://www.debian.org/security/2021/dsa-5023
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html